feat(billing): wire pruneDeadTokens into onEntitlementChanged

functions/src/billing/onEntitlementChanged.ts

@@ -1,5 +1,6 @@
 import * as functions from 'firebase-functions'
 import * as admin from 'firebase-admin'
+import { pruneDeadTokens } from '../notifications/pruneTokens'
 
 /**
  * Notifies the OTHER partner when a user GAINS premium, so couple-shared premium unlock isn't silent
@@ -110,5 +111,6 @@ export const onEntitlementChanged = functions.firestore
         console.warn(`[onEntitlementChanged] send failed ${tokens[i]}: ${String(r.reason)}`)
       }
     })
+    await pruneDeadTokens(db, partnerId, tokens, results)
     console.log(`[onEntitlementChanged] notified ${partnerId} of couple premium (${coupleId})`)
   })